Garbarino, a respected authority on juvenile violence and aggression (Lost Boys ), takes a fascinating look at girls getting physical—from the assertive physicality expressed by healthy girls to criminal violence on the part of troubled ones. He lauds girls' release from the obligation to be "ladylike" in an increasingly egalitarian society, a "new freedom... [that] can boost self-esteem and self-confidence." But at the other end of the spectrum are girls who are more vulnerable to today's increasingly "toxic social environment"—a deleterious entanglement of hypersexuality and materialism—and prone to asocial violence. Garbarino cites U.S. Justice Department statistics that the rate of girls arrested for assault is approaching that of boys. Examining biology, early childhood development and the effects of mass media, he builds on the work of other psychologists and social historians while adding texture to his accessible narrative with first-person accounts of girls' experiences—X-rated name-calling, punching, brawls with baseball bats. Society, he asserts, should allow girls to be "physical and popular in a nonsexual and nonmaterialistic way." What girls need, he concludes in this evenhanded but eye-opening book, is positive identity, a sense of rootedness and spirituality, and benevolent adult involvement in their lives. (On sale Feb. 20)